In recent years, various types of treatments and diagnoses in the medical field have been performed using an elongated and hollow tubular-shaped medical instrument called a catheter. Examples of such treatment methods include directly administering an agent into an affected area by using the elongated configuration of the catheter, push-opening a narrowed section in a lumen of a living body by using a catheter in which a balloon expanded by pressure is attached to a distal end of the catheter, scraping and opening the affected area using a catheter in which a cutter is attached to a distal section of the catheter, and closing arterial aneurysm, bleeding, or feeding vessel sites with a filling material by using the catheter. Other examples also include a treatment method of embedding and placing a tubular-shaped stent which has a mesh-shaped side surface into the lumen of the living body using the catheter so as to maintain an open state of the narrow section in the lumen of the living body. Further, examples include suctioning an excess liquid for a body in the body.
In general, in a case where the treatment, diagnosis, or the like is performed using the catheter, a catheter introducer is used to introduce an introducer sheath into a puncture site formed in an arm or a leg and the catheter or the like is percutaneously inserted into a lesion area such as a blood vessel via a lumen of the sheath for an introducer. Compared to trans femoral intervention (TFI) in which the an introducer sheath is introduced from a foot, trans radial intervention (TRI) in which the an introducer sheath is introduced from the arm has the advantage of facilitating hemostasis, shortened rest time, fewer bleeding complications, and the like for both patients and hospitals.
The introducer sheath is formed from a sheath tube that is a tubular member which has a hollow section into which an elongated body such as the catheter can be inserted. An example is disclosed in Japanese Application Publication No. 8-131552. The introducer sheath includes a distal section that is a distal side during the introduction into the puncture site, and a main body section that is placed on a proximal side of the distal section.
It is preferable that the wall thickness of the introducer sheath be reduced so that the outer diameter of the sheath is decreased or so that an elongated body that has a large outer diameter can be inserted.
When the wall thickness of the introducer sheath is reduced, there is a possibility that the distal section could curl when the introducer sheath is introduced into the puncture site.
Further, even in a case where the wall thickness of the introducer sheath is reduced, it is necessary to ensure the flexibility of the main body section in order to increase the penetrability of the elongated body such as the catheter. By ensuring the flexibility of the main body section, kinking can be inhibited or prevented and resiliency can be obtained to return to an original shape even in the case of the kink.
In prior introducer sheaths, the curling of the distal section is not improved and the flexibility of the main body section is not ensured even when the wall thickness of the main body section is reduced.